The present invention relates to a locking mechanism for a rotary power device and, more particularly, to a manually operable locking mechanism for a rotary power tool which permits a rotatable spindle of the tool to be temporarily locked against rotation to allow attachments to be safely connected to and removed from the spindle.
In the field of rotary devices, e.g., hand operated electric drills, sanders, and polishers, it has been proposed to provide locking mechanisms which permit an operator to temporarily lock the device against rotation to allow safe handling of accessories, e.g., drill chucks, sanding discs, and polishing wheels, to be attached to and removed from the power devices. The prior art shows various shaft locking mechanisms using spring devices, such as the coil spring and lock pin shown in U.S. Pat. No. 3,873,863 issued to The Singer Company, the assignee of the instant invention. When using a coil spring, the spring must be fitted between the spindle and the housing of the rotary power device, which space is generally too small to be able to accommodate a strong and sturdy coil spring which will perform adequately over the life of the power tool. The instant invention overcomes the problems inherent with using a coil spring and locking pin to lock the spindle of a rotary power tool.